Studies on T-shaped one-side bolted connection to hollow section column under bending

Abstract

A novel T-shaped One-side Bolted endplate Connection (TOBC) for steel beam to Hollow Square Steel Tube (HSST) was proposed and the behavior of TOBC under static bending moment was investigated through Finite Element Model (FEM). The FEM was verified by test results on Standard High-strength Bolted Connection (SHBC) in terms of the failure mode, the bending moment-rotation curve and the yield bending moment. Parametric analysis of TOBC was carried out. Studied parameters included both the general parameters of an endplate connection, such as the endplate width, the endplate thickness, the endplate strength, the bolt diameter, the bolt pretension force, the axial compression ratio of the column and the beam length, and the unique parameters of the TOBC, such as the direction of slotted bolt hole, the gap between infill block and bolt hole, the angular deviation of the T-head and the two-bolt hole of T-shaped One-side Bolt (TOB). A total of six failure modes were found namely: the beam yielding failure, the bolt failure, the endplate yielding failure, the column wall yielding failure, the column wall yielding accompanied with endplate yielding failure and the column wall yielding accompanied with bolt failure. The TOBC with slotted bolt hole in vertical direction had better performance than that in horizontal direction in terms of the initial stiffness, the yield bending moment and the ultimate bending moment. The gap between infill block and bolt hole had no effect on the bending performance of TOBC in moment connection. The angular deviation of the T-head had little influence on the bending performance of TOBC, if it was less than 30 degrees. The initial stiffness and yield bending moment of TOBC could be greatly increased by using two-bolt holes in the connection tension region.